Author Topic: Engine / Gearbox / Drive alignment / movement  (Read 1550 times)

PeterPortugal

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Engine / Gearbox / Drive alignment / movement
« on: February 24, 2021, 19:33:40 »
Gents,

I pulled the subframe out some time ago to rebuild it. I decided to do the gearbox mount too. Then I thought I might as well get the propshaft done....you know how it goes.

Anyway now I have put it all back together it is clear the alignment of the engine / gearbox and prop shaft are well out.

What have I noticed?
1. The bearing bracket for the prop shaft is not perpendicular to the axis of the car. By this I mean the nuts which slide are not at the same point in the two slots. One is clearly further backwards.
2. The gearbox mount screw which bolts to the stiffener plate does not readily locate in the slot which it passes through.

I need to move the engine sideways by a good few mm, maybe half an inch. How do I actually move the engine? Do I have to loosen off the subframe mounting bolts to get it to move? The lateral locating rod is not fitted.

The above is all things which are clearly out by the eye. I am not worried about the wheel geometry aspect of the alignment. That will come after this basic element is correct.

Regards

Peter
1963 220se Cabrio
1968 280se Coupe

Leester

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Re: Engine / Gearbox / Drive alignment / movement
« Reply #1 on: February 24, 2021, 21:06:14 »
Hello Peter, I just did this same process on my 280SL project and fortunately everything aligned properly (with one unrelated exception). The only thought that comes to mind is if you have one of the arms that come off the side of the engine over to the motor mounts upside down or possibly reversed left arm to right side and vice versa that might cause your misalignment. I doubt that you have the arms reversed left to right since the left arm also has provision for the fuel filter that the right arm doesn't. My recollection is that the position of the motor mounts on the front subframe are not adjustable. 
Lee Backus
1963 220SE Cabriolet
1970 280SL (reassembling - hopefully soon)
1978 450SL (disassembled for paint)
1985 500SEC

PeterPortugal

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Re: Engine / Gearbox / Drive alignment / movement
« Reply #2 on: February 24, 2021, 22:37:46 »
Hi Lee,

Thanks for replying but engine never left the car. I supported it under the oil pan and the gearbox.Motor mounts untouched.

I did move the whole engine / subframe about a bit when re-installing it before I bolted iup the subframe mounts.

I have decided to loosen the subframe mounts again whilst taking the weight on an engine crane and see if I can move it about a bit.

Cheers

Peter
1963 220se Cabrio
1968 280se Coupe

Leester

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Re: Engine / Gearbox / Drive alignment / movement
« Reply #3 on: February 25, 2021, 01:57:09 »
OK, so you didn't remove the engine, just the subframe. Now you've reinstalled the engine and the arms are sitting on the motor mounts which are sitting on the subframe. Sounds like maybe the subframe might be off kilter. Have you attached the front leaf springs yet?
Lee Backus
1963 220SE Cabriolet
1970 280SL (reassembling - hopefully soon)
1978 450SL (disassembled for paint)
1985 500SEC

PeterPortugal

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Re: Engine / Gearbox / Drive alignment / movement
« Reply #4 on: February 25, 2021, 07:56:23 »
Hi Lee,

The situation is as you describe. The motor mounts are fitted and the subframe bolts are fitted. The front leaf springs and the lateral rod are not fitted.

Regards

Peter
1963 220se Cabrio
1968 280se Coupe

Leester

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Re: Engine / Gearbox / Drive alignment / movement
« Reply #5 on: February 25, 2021, 17:23:41 »
Hi Peter, installing the front leaf springs might pull the subframe into proper alignment. Its worth a try and you have to do it sooner or later. I believe the leaf springs are part of the front end alignment, caster adjustment I think, so when you install them, you want them in the centered position as much as possible so there is room to make the alignment adjustments. You may have to search caster adjustment or similar to get more expertise than I can provide.

If it were me, attaching the leaf springs would be my next move. I assume the lateral rod is what I call the sway bar and I am not sure if attaching that would help your situation, again maybe someone with more expertise can weigh in.

Good luck.

Lee
Lee Backus
1963 220SE Cabriolet
1970 280SL (reassembling - hopefully soon)
1978 450SL (disassembled for paint)
1985 500SEC